Power electronic devices are often utilized in high-power electrical applications, such as inverter systems for hybrid electric vehicles and electric vehicles. Such power electronic devices include power semiconductor devices such as power insulated-gate bipolar transistors (IGBTs) that are thermally bonded to a substrate. With advances in battery technology in electrified vehicles and increases in electronic device packaging density, operating temperatures of power electronic devices have increased and are currently approaching 200° C. which result in increased thermomechanical stresses endured by the power electronic device. Accordingly, stress mitigation structures or materials for power electronic devices are desired. Due to coefficient of thermal expansion (CTE) differences between the power semiconductor device, the bonding layer, and the substrate, thermally induced stresses may cause damage to the bonded assembly. Although bond layers formed by transient liquid phase bonding results in a bond layer having a high melting temperature greater than 200° C., such TLP bond layers are very hard and brittle. Thus, they are susceptible to thermally induced stress damage.